Mr. E. J. Miers on a Freshioater Crustacean. 195 



termiual postabclominal segment not acute, but somewhat 

 rounded at its distal extremity ; the number of rostral teeth 

 (in five specimens) varies between ^ and y. 



I may be allowed to point out, moreover, that the presence 

 of these palpiform appendages (exopodites) both in Atyephyra 

 and the nearly allied genus, Troglocarisy Dormitzer *, which 

 inhabits caves in Carinthia, necessitates the removal of these 

 genera from the subfamily Atyina3 to the Ephyrinaj, as cha- 

 racterized by Mr. Kingsley in his very useful synopsis of the 

 genera of Crangonidte, Atyidaj, and Palasmonidaj f- 



Troglocaris differs from Atyephyra in its rudimentary eyes 

 and in the more largely dilated penultimate joints of the tho- 

 racic limbs ; Miersia \Ephyra) has a marine habitat, and, as 

 von Martens has shown, is distinguished by possessing a 

 mandibular palpus \, by the position of the inferior lateral 

 spine of the carapace, the carinated postabdomen, and by other 

 characters. 



As regards specific distinctions, the specimens received from 

 Tokio differ from De Haan's original description of ^. com- 

 pressa in having the rostrum armed with fewer teeth on the 

 upper and lower margins, and the postabdominal appendages 

 biramose, not simple^ as stated by De Haan. In the figure 

 in the ' Fauna Japonica,' however, they are represented as 

 biramose ; so possibly De Haan's description is after all in- 

 correct as regards this particular. With regard to the 

 dentition of the rostrum, De Haan says that the upper margin 

 has twenty to twenty-four teeth, and the lower margin four 

 teeth ; the largest number of rostral teeth in any specimen I 

 have examined is y and y ; this, however, is a very 

 variable character, since scarcely two specimens out of fifteen 

 examined by me were found to agree exactly in this particu- 

 lar ; in one there were only | teeth. Von Martens figures 

 an example with | teeth. There can, I think, be no doubt 

 of the specific identity of his specimens (which were obtained 

 at Yokohama) with ours ; but it remains for naturalists work- 

 ing in the country and with larger material to determine 

 whether this species be indeed the Atyephyra'^ compressa (De 

 Haan) or a distinct but closely allied form. 



* Lotos, iii. p. 85, pi. iii. (18o3). 

 t Proc. Acad. Nat. Sci. Philad. p. 415 (1879). 



X Mr. Kingsley 's diagnosis of his family Atjidae needs emendation as 

 regards this character. 



